Prof Gray - Done

Question 1

Why is it important to coordinate behaviour between cells?

Answer 1

to ensure that a response to a stimulus involves the cells working together

Question 2

What is endocrine signalling?

Answer 2

use of hormones to signal via the bloodstream

Question 3

what type of signalling system does insulin belong to?

Answer 3

endocrine

Question 4

what type of cells receive signals from the endocrine system?

Answer 4

all cells, only some respond

Question 5

what scale is paracrine signalling on?

Answer 5

neighbouring cells only

Question 6

what are histamine and nitric oxide examples of?

Answer 6

paracrine signalling

Question 7

what type of cells use neuronal signalling?

Answer 7

neurones

Question 8

where are neuronal signalling molecules released?

Answer 8

synapses between neurones

Question 9

what is acetylcholine an example of?

Answer 9

neuronal signal

Question 10

what is a key feature of a single type of neurotransmitters?

Answer 10

they can be used for more than one response

Question 11

Where are direct contact signals?

Answer 11

in the PM

Question 12

what is a delta signal a type of?

Answer 12

direct contact signal

Question 13

how do intracellular signals work?

Answer 13

the signal diffuses through the PM of the cell

Question 14

name the 2 types of intracellular activity?

Answer 14

enzyme activity and gene expression

Question 15

how do intracellular receptors impart activity on an enzyme?

Answer 15

binding changes 3D conformation

Question 16

Name an example of an intracellular signal which imparts enzymatic activity?

Answer 16

Nitric oxide

Question 17

How is the nitric oxide pathway utilised in viagra?

Answer 17

NO binds to enzyme stimulating cGMP production

Question 18

How can intracellular receptors regulate gene expression?

Answer 18

Travel through PM and bind to receptor allowing DNA binding

Question 19

What allows ligand gated ion channels to open and close?

Answer 19

signal binding/un-binding changes the 3D conformation

Question 20

Where are ligand gated ion channels commonly used?

Answer 20

neurone synapses

Question 21

Kinases impart enzymatic function on membrane proteins, how is this done?

Answer 21

Dimerisation takes place

Question 22

How many passes across the membrane take place in G protein receptors?

Answer 22

7

Question 23

What is the result of the signal binding to a G protein couple receptor, in terms of the G protein?

Answer 23

The receptor allows the G protein to bind to GTP

Question 24

What does the G protein do when bound to GTP and released rom the receptor?

Answer 24

It binds to an effector enzyme activating it

Question 25

What does the Ras protein bind to allowing activation of a kinases cascade?

Answer 25

GTP

Question 26

What type of enzyme is Ras?

Answer 26

GTPase

Question 27

what is the result of a protein kinase cascade?

Answer 27

cell proliferation

Question 28

When is Ras switched off?

Answer 28

when GTP is broken down to GDP

Question 29

Why can mutant forms of Ras result in cancerous cells?

Answer 29

They are not GTPases meaning that cell proliferation is not switched off

Question 30

What does Phospholipase C produce as a secondary messenger?

Answer 30

PIP2/IP3 (same thing)

Question 31

How does PLC make PIP2?

Answer 31

cleaves a membrane lipid

Question 32

When PIP2 binds to its receptor what effect takes place?

Answer 32

Ca2+ are released allowing further activation of enzymes

Question 33

What does GPCR stand for?

Answer 33

G protein coupled receptors

Question 34

What is a common secondary messenger for GPCRs?

Answer 34

cAMP

Question 35

What does cAMP production usually lead to the activation of?

Answer 35

Protein kinase cascade

Question 36

If a process leads to the production of one signal and the activation of an enzyme, why might a totally different enzyme also be activated?

Answer 36

Signalling pathways are heavily cross linked